#define _CRT_SECURE_NO_WARNINGS 1
/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
	TreeNode* traversal(vector<int>& nums, int left, int right)
	{
		if (left > right) return nullptr;
		int mid = left + ((right - left) / 2);
		TreeNode* root = new TreeNode(nums[mid]);
		root->left = traversal(nums, left, mid - 1);
		root->right = traversal(nums, mid + 1, right);
		return root;
	}
	TreeNode* sortedArrayToBST(vector<int>& nums) {
		TreeNode* root = traversal(nums, 0, nums.size() - 1);
		return root;
	}
};